Warning sign devices, particularly those having a triangular appearance and adapted to be assembled into an upright position from a collapsed, storage configuration have come into extensive use, particularly by trucks and truck drivers, since the issuance of United States Government Motor Vehicle Safety Standard No. 125 (effective Jan. 1, 1974). Such a structure is shown for example in Lindner and Kennedy U.S. Pat. No. 3,773,012 (issued Nov. 20, 1973).
Various mounting means have been used to support such a warning sign device in an upright position for use. One such mounting means is taught by Lindner and Kennedy U.S. Pat. No. 3,863,880 (issued Feb. 4, 1975). Actual field usage of such combinations of such warning devices with such mounting means has revealed that they all suffer from a common failing: Wind blowing against an assembled such warning sign device tends to cause same to move and to assume such a configuration relative to the associated base member that the entire assembled combination collapses. This problem is of such proportions that the State of California has now adopted standards and regulations which, in effect, require that all new warning devices sold in that State must have a mounting support assembly capable of holding the warning sign device in an upright, operable position indefinitely against strong surface winds.
So far as I am aware, prior to my present invention, no support assembly was known which would meet the State of California requirements for wind resistance in such combinations, and, at the same time, still provide collapsibility (storageability) for the entire assembly of warning device and support assembly.
Also, so far as I am aware, prior to my present invention, combination of mounting support and warning sign device was known which would permit the warning sign device to be detachably secured to the mounting support without adversely affecting wind resistance requirements such as those set by the State of California. Such detachability is desirable in order to permit replacement of the warning sign device without having to replace the mounting support (should, for example, the warning sign device be accidentally broken in use).